Inside Sweden’s A26 Blekinge-Class: The World’s First Fifth-Generation Conventional Submarine

Sweden has long been recognized as one of the most innovative nations in submarine technology, and the unveiling of the A26 Blekinge-class marks a significant leap forward in naval warfare. Claimed to be the world’s first fifth-generation conventional submarine, the A26 is designed not only to strengthen Sweden’s maritime defense but also to integrate seamlessly into NATO’s evolving concept of Multi-Domain Operations (MDO). This ambitious project reflects Sweden’s dual strategy: modernizing its submarine fleet while preserving its domestic industrial base in underwater systems.

A26 Blekinge-class. Photo: Saab

Key Features of the A26 Blekinge-Class Submarine

The A26 Blekinge-class introduces a suite of advanced features that distinguish it from previous generations of conventional submarines. Central to its design is multi-domain signature management, which allows the vessel to minimize its acoustic, magnetic, radar, electrical, infrared, and visual signatures. This makes detection by adversaries significantly more difficult, enhancing survivability in contested waters.

Another groundbreaking feature is the Stirling Air-Independent Propulsion (AIP) system. Unlike traditional fuel cell technology, Stirling AIP enables the submarine to remain submerged for several weeks without surfacing, offering superior endurance and operational efficiency. This capability is critical for stealth operations in areas where surfacing would compromise mission secrecy.

The A26 also incorporates a Multi-Mission Portal, a versatile system that supports the deployment of unmanned underwater vehicles (UUVs), swimmer delivery vehicles (SDVs), and special operations forces at depth. This portal transforms the submarine into a multi-role platform capable of conducting reconnaissance, sabotage, and covert insertion missions.

Equally important is the submarine’s “bottoming” capability, which allows it to rest silently on the seabed. This tactic provides camouflage and operational flexibility, enabling the vessel to evade detection while awaiting mission execution. Finally, the A26 is built with system-of-systems integration, ensuring it can operate in concert with surface ships, other submarines, and aerial assets to deliver layered situational awareness.

Role of the A26 in NATO Multi-Domain Operations

The Blekinge-class is not merely a weapon of stealth; it is a node in NATO’s broader MDO framework. Equipped with advanced electronic surveillance and communication systems, the submarine can collect intelligence and relay data to NATO’s command networks. This ensures that information gathered underwater contributes directly to joint operations across land, air, cyber, and space domains.

Artificial intelligence-assisted data processing further enhances the submarine’s role, enabling rapid synchronization with allied assets. This capability supports the emerging concept of “underwater information warfare,” where submarines exploit enemy communications while safeguarding critical undersea infrastructure such as cables and pipelines.

At the heart of its combat capability lies the Saab 9LV Combat Management System (CMS). This advanced C4I (Command, Control, Communications, Computers, and Intelligence) solution allows the A26 to coordinate missions across multiple platforms, ensuring seamless integration into NATO’s operational architecture.

Technical Specifications of the A26 Blekinge-Class

The A26 Blekinge-class is a medium-sized submarine with a surface displacement of 1,925 tons and a submerged displacement of 2,100 tons. Measuring 66.1 meters in length, 6.75 meters in beam, and with a draught of 6 meters, it is optimized for both coastal defense and extended patrol missions.

Propulsion is provided by two diesel-electric engines supplemented by four Stirling AIP MkV V4-275R units. This hybrid system grants the submarine an endurance of up to 45 days submerged, with 18 days achievable solely on AIP. Maximum speed is approximately 20 kilometers per hour, sufficient for stealthy maneuvering in contested waters.

Crew capacity ranges from 17 to 26 personnel, with the option to expand to 35 when accommodating special operations forces. Armament includes four 533 mm torpedo tubes capable of firing Torped 62/63 heavy torpedoes, and two 400 mm tubes for Torped 47 lightweight torpedoes or the new Swedish Lightweight Torpedo (SLWT). Modular payload options allow the integration of cruise missiles or seabed-deployed munitions.

Sensor systems are equally advanced, featuring Atlas Elektronik sonar suites (Bow sonar, Conform flank array sonar,HF intercept sonar arrays), the Kongsberg (SA9510S Mine Avoidance and Navigation Sonar, EM2040 multibeam echo sounder, side-scan sonar, sub-bottom profiler and hydrographic echo sounders), and Safran Series 30 optronic masts. Together, these systems provide comprehensive detection, tracking, and targeting capabilities in complex underwater environments.

Program History of the A26 Blekinge-Class

The origins of the A26 project trace back to the U-båt 2000 concept of the 1990s, which was shelved following the end of the Cold War. The program was revived in 2010 to replace the aging Södermanland-class submarines.

In 2014, Saab acquired Kockums after disputes with ThyssenKrupp, consolidating Sweden’s submarine design expertise under a national company. The following year, a contract was signed for two A26 units valued at SEK 8.2 billion.

By 2021, the program faced delays and cost increases, with the contract renegotiated to SEK 14 billion and delivery postponed to 2027–2028. In 2025, a new agreement with the Swedish Defence Materiel Administration (FMV) raised the cost ceiling to SEK 25 billion ($2.3 billion), with delivery targets set for 2031 and 2033. An additional SEK 9.6 billion was allocated for final production phases between 2026 and 2032.

Export Variants of the A26 Submarine

Recognizing the global demand for advanced conventional submarines, Saab has developed several export variants of the A26 platform.

• Pelagic Variant: A compact 50-meter design optimized for coastal defense, with endurance of 20 days.
• Oceanic Variant: The baseline model offering endurance beyond 30 days, suitable for regional patrols.
• Oceanic Extended Range: A larger design exceeding 80 meters in length, capable of more than 50 days endurance and ranges over 10,000 nautical miles.
• C71 Expeditionary: A long-range variant with endurance exceeding 13,000 nautical miles, derived from both the Blekinge-class and Australia’s Collins-class experience.

These variants allow Saab to tailor the A26 platform to the specific needs of international customers, from littoral defense to global expeditionary operations.